Device for continuous casting of metal

ABSTRACT

An electromagnetic field is produced in a flow of molten metal by a coil surrounding the flow in order to establish forces in the flow. A coolant is applied to the solidifying and solidified surface of the ingot produced from the flow. A thin non-magnetic screen in positioned between the coil and the flow and insulating material is positioned between the screen and the coil. Coolant is also applied to the screen.

w SWWS tent 1 1 1111 3,735,7@@ Karlson ay 29, 1973 [54] DEVICE FOR CONTINUOUS CASTING [56] References Cited OF METAL UNITED STATES PATENTS [75] Inventor: Karl Gosta 1 Karlson, Vasteras, Sweden 3,467,166 9/1969 Getselev et a1. ..l64/250 x 3,605,865 9/197] Getselev ..l64/250 [73] Assignee: Allmanna Svenska Elektriska Aktiebolaget, Vasteras, Sweden Primary ExaminerRobert D. Baldwin [22] Filed, Mar 1 1971 Att0rney-Kenyon & Kenyon Reilly Carr & Chapin [21] Appl. No.: 119,776 [57] ABSTRAT I 1 An electromagnetic field is produced in a flow of mol- [30] Foreign Application Priority Data ten metal by a coil surrounding the flow in order to establish forces in the flow. A coolant is applied to the Mar. 3, 1970 Sweden ..2740/70 solidifying and solidified Surface of the ingot produced t [52 us. (:1. ..164/147, 164/250, 164/283 {mm he flow A magnetic Screen- Int Cl Bzzd 11/00 Bzzd 27/02 tioned between the coil and the flow and insulating I I n u 6 6 6 6 6 u 6 6 6 I I 6 t l t d b t n d 0'1I 58 Field of Search 164/250, 251, 147, m cm posl 8 wee e Screen an e c Coolant is also applied to the screen.

2 Claims, 2 Drawing Figures DEVICE FOR CONTINUOUS CASTING OF METAL BACKGROUND OF THE INVENTION The present invention relates to a means for continuous casting, comprising at least one induction coil to produce an electromagnetic alternating field in a flow of molten metal in order to build up forces in this flow, directed towards the flow.

If the frequency, voltage, etc. of the single phase a]- ternating current in such a coil, are suitably chosen, sufficient forces directed towards the flow can be generated such that a column of melt which has not solidified will be held together laterally without spreading and without the need for chill or mould walls, a uniform surface then being obtained for the ingot. At the same time an ingot is obtained without blisters or burrs. Coolant, such as water, is applied to the surface of the solidifying or solidified ingot in the crystallizing zone of the ingot. Such a casting technique has been used in practice for casting tin or aluminum or metals and alloys having approximately the same melting points, whereas because of temperature or other reasons it has not been possible to use this method on metals or alloys, such as iron or steel, which are more difficult to melt.

STATEMENT OF THE INVENTION THE DRAWINGS The invention is illustrated in the accompanying drawings where FIG. 1 shows a longitudinal crosssection of the casting means, and FIG. 2 a lateral crosssection through the coil and ingot.

PREFERRED EMBODIMENT FIG. 1 shows how a metal stream 11, for example molten steel, is tapped in the vicinity of a single-phase alternating field from an induction coil 12 having one or several turns. Due to the influence of the field from the winding, inwardly directed forces are generated because of the pinch effect, which forces hold a column of molten metal 13 together so that no chill or mould walls are required. The ingot column 17 of solidified and unsolidified melt is carried by a base 14 which is lowered at the desired casting rate.

The column is sprayed with coolant (at 15) close to the crystallization zone of the ingot, thus accelerating the solidification, particularly at the outer surface of the ingot. Due to the flow forces, an inner pressure is obtained in the metal, which results in homogeneous casting.

According to the invention a thin screen 16 of nonmagnetic material, such as stainless steel, is placed between the column 13-17 and the coil 12 to protect the turns of the coil against high temperature radiation and the moist atmosphere. Coolant flows through the turns of the winding in the normal manner. The screen 16 is in the form of a casting around the melt column 13-17. The screen is electrically insulated from the coil by some suitable insulating means, such as ceramic .or organic insulating material as shown in FIG. 2. Due to the water spray the screen is kept at such a low temperature that it maintains its mechanical strength during the casting process and at the same time conventional insulating material can be used around the coil due to the protective action of the screen.

By arranging the coil turns along a considerable length of the ingot, the continuous casting can be carried out at a relatively high speed.

I claim:

1. Means for continuous casting an ingot, comprising at least one coil to produce an electromagnetic field in a flow of molten metal in order to generate forces directed towards said flow, said coil adapted to axially extend a substantial distance along the solidified ingot from the nonsolidified portion of the ingot, an enclosed protective screen of non-magnetic material arranged inwardly along the entire length of said coil, means to conduct a coolant towards the nonsolidified portion of said ingot, said screen being arranged in relation to the coolant conductor in such a way that, during the casting, it is sprinkled with coolant from the inside.

r 2. Means according to claim 1, including insulating means for the winding placed between the screen and .the coil.

i i i i t UNITED STATES PATENT @EEECE TWMIATE @F @RRECTN Dated M y 29; 1W3

, Pat n No 3.735399 Inventor(s) Karl GBsta K811158021 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected es shown below:

Correct the inventor's name to read:

I ---Kari GBsta Karls son- Signed and sealed this 25th day of Deeember 19739 (SEAL) Attest:

EDWARD M.ELETGHER,JR. RENE Do TEGTMEYER Attesting Officer Acting Commissioner of Patents U.S. GOVERNMENT PRINTING OFFICE: I959 0-366-334 FORM PO-IOSO (10-69) 

1. Means for continuous casting an ingot, comprising at least one coil to produce an electromagnetic field in a flow of molten metal in order to generate forces directed towards said flow, said coil adapted to axially extend a substantial distance along the solidified ingot from the nonsolidified portion of the ingot, an enclosed protective screen of non-magnetic material arranged inwardly along the entire length of said coil, means to conduct a coolant towards the nonsolidified portion of said ingot, said screen being arranged in relation to the coolant conductor in such a way that, during the casting, it is sprinkled with coolant from the inside.
 2. Means according to claim 1, including insulating means for the winding placed between the screen and the coil. 